During cable manufacture, and in particular when manufacturing electric cables, it is necessary to store partially fabricated lengths from one operation before passing on to a subsequent operation.
Such storage serves, for example, to mitigate the effects of differences in operating speed between assembly lines for performing successive operations on a cable. Furthermore, it provides "slack", enabling a repair to be performed on the site of some incident in one assembly line without having to stop the entire manufacturing operation.
All the processes in cable manufacture have been automated except for coiling down, ie. the operation of filling a cable tank with cable by winding coils of cable outwardly on one layer then inwardly on the next layer and so on to build up plane layers of spiraling cable until the tank is full. To ensure that the turns are contiguous, it is necessary for a coiler to push on the cable while it is being coiled inwardly and to pull on it while it is being coiled outwardly.
At present this operation of coiling down is performed entirely manually, including one or more coilers working inside the tank. The job is monotonous and unrewarding. Further, to ensure that it is performed properly, operators have to be replaced at frequent intervals. It is becoming difficult to find personnel willing to work under such conditions.
Semi-automatic machines for coiling down have already been proposed which either enable the number of operators or coilers handling the cable to be reduced, or else lighten the load when heavy cable is being coiled. However, in either case, these semi-automatic machines still require personnel to work at the bottom of the tank.
Preferred embodiments of the present invention enable human intervention to be dispensed with for substantially the entire period it takes to fill a tank, say three days. A coiler may still be required to assist the machine while the first few turns are being laid, and then again when the tank is filled up. Nevertheless, a single coiler can thus supervise a plurality of machines.